08 July 2006

Part of the charm of driving on Mexico’s highways comes from the fact that there are no billboards desecrating the landscape. The only exception to this ban on advertising is a single liquor company which, for mysterious historical reasons, has the right to put up giant cutouts of bulls but these, mercifully, are few and far between. But, if you are in Mexico City, getting on the appropriate highway may well be your worst challenge—to say merely that the traffic is awful gives little indication of just how much patience and dedication it requires. It took us several hours last week, just after Germany demolished a surprisingly inept Argentina on penalties, before we were on our way to Oaxaca, perhaps the most diverse and easily the least adequately protected of Mexico’s states. (Though Oaxaca contains only 5 per cent of the area of Mexico, it contains 50 per cent of thetotal known vascular plant species for the country, 35 per cent of the total amphibian species, 26 per cent of the reptile species, 63 per cent of the bird species, and 55 per cent of the terrestrial mammal species).

The six-hour drive to Oaxaca takes you through a variety of landscapes including the 490 000 hectare Tehuacán—Cuicatlán Biosphere Reserve which straddles the border between Puebla and Oaxaca. This Reserve is huge: if you include it among the protected areas of Oaxaca, about 12 per cent of the state is already under protection. But, if you don’t, only 0.3 per cent of Oaxaca is protected, all in three tiny National Parks. The argument against inclusion is that the Reserve, though situated in a biologically important and unique habitat (the southern limit of the North American deserts), is in far from prime condition. The Reserve is made up of wide arid valleys bordered by much more humid forested ranges. There are more than 170 endemic flowering plant species within it and the diversity of columnar and candelabra cacti is exceptional. The heat was intense. Our view from the road was typically of an otherworldly landscape, spiny shrublands dotted with columns of cacti. The toll road goes through relatively intact habitat but this is misleading. In Oaxaca, 35 000 people live within the Reserve; between both states, the human population is over 250 000.

Deforestation rates are high in much of Oaxaca but we drove through so
much relatively wild land on the way that there is still a lot of
opportunity to develop good conservation plans for the state. I was on
a field trip organized by my long-time collaborator, Victor
Sanchez-Cordero, and students from his laboratory at UNAM. We had been
working on data from Oaxaca for some time now—primarily with Victor’s
student, Patricia Illoldi—and this was my chance to see the region
before we found ourselves in print making recommendations on land use!

Our truck had seen better days but I was seated comfortably in the
front seat while Victor survived six rattling hours in the back. The
night saw us at a pleasant hotel with excellent food on the outskirts
of Oaxaca city. The city itself was in turmoil because of a month-long
teachers’ strike over pay and benefits. (I heard nothing positive said
about the state’s governor who is the target of the teachers’
protests.) With the Mexican presidential election a mere two days away,
there was additional tension in the streets. Rumors floated of highway
traffic being blocked by teachers on the day after the election. (It
was probably a good thing that tomatoes were not to be found, at least
in our hotel’s restaurant.) But the peaceful hotel garden was flooded
with birds at dawn—the Andean Sparrow (Zonotrichia capensis) and the
Green-fronted Hummingbird (Amazilia viridifrons) were welcome additions
to my list. Tropical Kingbirds (Tyrannus melancholica) mingled with
Vermilion Flycatchers (Pyrocephalus rubinus).

The field site was within a 10 000 hectare communal reserve, La
Cumbre—Ixtepeji Parque Ecoturistíco, in the Sierra Norte de Oaxaca,
along Highway 175 northeast of the city. Much of this area, Santa
Catarina—Ixtepeji, is communally governed, fiercely resisting external
interference, for instance, by refusing to follow daylight savings
time. For accommodation within the Park, there were dormitories and
cottages with dim lights and running water, as well as places to pitch
a tent. A tiny restaurant near the Park headquarters provides simple
but excellent food in large quantities so long as you warn the cook in
advance. Nights were cold at about 2 500 m. but there were fireplaces
in the rooms. As is often the case in tropical nature “retreats,”
nights were not quiet near the residential areas; other visitors played
loud music ino the night—but this is about the only possible criticism
of the facilities. A playground near the park provided excellent
birding, with several pairs of American Robins (Turdus migratorius)
nesting nearby. The success of conservation at this Park here has been
so impressive that it now receives recognition and help from WWF. It is
almost certain that this success is due to communal rather than state
ownership and management which comes with local emotional investment in
the success of the scheme. The Park provides a model that can be
profitably replicated elsewhere, especially in the neotropics.

Even by Oaxaca’s high standards these northern mountains have extraordinary diversity, over 4 000 species of plants, 485 species of birds, and 350 species of mammals (according to pamphlets produced by WWF). We were in the middle of the rainy season and the landscape was exceptionally green, so much so that it was hard to imagine that we were but a short distance from the hot desert landscapes of the Tehuacán—Cuicatlán Biosphere Reserve we had passed earlier. Spanish moss and epiphytes were everywhere. We found at least ten species of mushroom, many of which were very large, edible, and collected for breakfast the next day.

It was hard to reconcile the apparent health of these forests with the
fact that much of them has been systematically logged within the last
generation. (Of this there is no doubt: there are plenty of stumps as
evidence.) Trails led from the dormitory area in different directions,
mainly to the adjoining peaks which offer breathtaking views of the
surrounding area. (The trails are only of moderate steepness but
sometimes slippery because of the daily rain.) What was remarkable was
the forest diversity between adjacent slopes. A trail we climbed
started mainly through oak and pine forests, and became entirely
dominated by the pines (Pinus leiophylla) near the top. (There was
plenty of coyote [Canis latrans] scat and a place where a puma [Puma
concolor] had killed a coyote trapped earlier by another of Victor’s
students.) Facing us across the valley was another slope also dominated
by pines, but primarily Pinus oaxacana. Such patterns were easy to
find, but not as easy to explain.

Fieldwork amounted to laying Sherman traps baited with oak for rodents
and putting up mist nets for bats, the latter both within the Park and
at a few localities outside. Bats have not been properly surveyed in
this region. Victor’s student, Francisco Botelli, had long worked in
this region, knew everyone, and arranged for the necessary permissions.
The Sherman traps caught an abundance of Peromyscus difficilis though
nothing else. Some of these will be tested for the presence of vectors
for Chagas’ disease which is a serious health problem in this region.
As for bats, within the park we only netted and released an Eptesicus
fuscus, besides several birds including a Yellow-eyed Junco (Junco
phaeonotus). But at a pond in Nuevo Zoquila, in a valley some distance
away from the Park, we netted two species of Myotis bats which resisted
identification and were, therefore, converted to specimens. (This is an
euphemistic way of saying that we killed them for our collections.) But
my main lesson from the fieldwork was how poor Mexican bird guidebooks
are: some banded warblers trapped in the nets resisted identification
by a group of seven biologists (though, admittedly, no ornithologist, and it was an LBJ--litle brown job).
My favorite bird in the trip was a Lesser Roadrunner (Geococcyx velox)
which flitted across the trail one evening in front of the truck.